Drilling machine



FIG. 1 is a top plan view of a drilling machine showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a side view taken from the left of FIG. 2;

FIG. 4 is a side view taken from the right of FIG. 1;

FIG. 5 is a back view thereof; and

FIG. 6 is a perspective view thereof. 

The ornamental design for a drilling machine, substantially as shown and described. 